This article presents the concept and steps of SPC, indicates the keypoints and lists the items to evaluate the SPC results.
本文对SPC的定义，实施的步骤作了论述，指出了其中的要点，并给出了评价SPC成果的指标。
2
These days, SIFT keypoints are arguably the most popular, since they can match images under different scales, rotations, and lighting.
这些天来， SIFT关键点可以说是最流行的，因为他们可以匹配不同尺度下，旋转和照明图片。
3
This is faster than simple SIFT keypoint matching, because it avoids the costly matching process, and keypoints are much simpler than SIFT, so keypoint extraction is much faster.